Posted in Lecture Notes

Clinical Microscopy – Automation

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WHAT’S IN HERE?

  • Principles Used in Automated Urinalysis and Microscopy
  • Automated Urinalysis Systems
  • Automated Body Fluid Analysis Systems
Principles Used in Automated Urinalysis and Microscopy
  • REFLECTANCE PHOTOMETRY
    • Used by automated reagent strip readers
    • Measure the light reflected from the reagent strip color pads and compare the amount of reflected light with a known standard
    • PRINCIPLE: light reflected from the colored reagent pads DECREASES in DIRECT PROPORTION to the INTENSITY OF THE COLOR produced by the reaction with the specific substance in the urine sample
      • the darker the color, the less light reflected
      • the lighter the color, the more light reflected
    • The concentration of a specific substance and concentration units are displayed on the reader’s display
  • LASER-BASED FLOW CYTOMETRY, IMPEDANCE & LIGHT SCATTER
    • Identify sediment elements in a urine sample
    • measures sediment conductivity and light scatter
      • Conductivity is based upon the impedance (the amount of resistance that occurs when a sediment passes through an electrical field) of sediments and counts the numbers of pulses (sediments).
        • The size of the pulse indicates the size of the sediment.
      • Light scattering characteristics of the sediments are determined by their movement through the laser light beam.
        • Identification depends on how the light is scattered by the sediment.
  • HARMONIC OSCILLATION
    • Assesses SPECIFIC GRAVITY
    • Method based upon densitometry in which a sound wave of a specific frequency changes in proportion to the density of the urine sample
    • Change in wave frequency is measured by a microprocessor and translates the reading to specific gravity
  • HYDRODYNAMIC FOCUSING
    • Identifies specific sediments
    • involves the movement of single urine sediments past the optics of a microscope to allow sediments to flow in several planes plane past the microscope objective
    • A flow cell also measures sediment conductivity, size, and light scattering traits
    • Questionable findings are viewed on a monitor for operator identification and confirmation
Automated Urinalysis Systems
  • INDIVIDUAL STRIP  READERS
  • SEMIAUTOMATED  ANALYZERS
    • dependent on an operator for specimen mixing, test strip, dipping,  and  inputting  of  physical  and  microscopic  results
  • FULLY  AUTOMATED CHEMISTRY ANALYZERS
    • add urine to the reagent strip
  • AUTOMATED URINE CELL ANALYZERS
    • mix, aspirate, dilute, and stain urine to classify urine sediment particles
  • COMPLETELY  AUTOMATED  SYSTEMS
    • perform a complete urinalysis that includes the physical, chemical, and microscopic parts of a routine urinalysis
WAIVED URINE CHEMISTRY INSTRUMENTS
Roche Diagnostics Criterion II Siemens Medical Solutions Diagnostics Clinitek®50 Siemens Medical Solutions Diagnostics Clinitek®101 Siemens Medical Solutions Diagnostics Clinitek®Status
SEMIAUTOMATED URINE CHEMISTRY INSTRUMENTS
Dirui Urine Analyzer H-50, 100, 200 Iris Diagnostics Division iChem®100 Roche Diagnostics URISYS®1800 Roche Diagnostics Chemstrip Criterion II Siemens Medical Solutions Diagnostics Clinitek®200, 200+, 500
FULLY AUTOMATED URINE CHEMISTRY INSTRUMENTS
Iris Diagnostics Division AUTION MAX® Iris Diagnostics Division iChem® VelocityTM Roche Diagnostics URISYS 2400® Siemens Medical Solutions Diagnostics Clinitek® Atlas
AUTOMATED SEDIMENT ANALYSIS
Iris Diagnostics Division iQ®200ELITETM Iris Diagnostics Division iQ®200SELECTTM Iris Diagnostics Division iQ®200SPRINTTM Sysmex UF-100® Urine Cell Analyzer
TOTALLY AUTOMATED URINALYSIS SYSTEMS
Iris Diagnostics Division iQ®200 Automated Urinalysis System iRICELL2000 (iChem® VelocityTM plus iQ®200ELITETM) iRICELL3000 (iChem® VelocityTM plus iQ®200SPRINTTM) Siemens Medical Solutions Diagnostics ADVIA Urinalysis WorkCell System (Clinitek® Atlas plus the Sysmex UF-100)
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DESCRIPTION OF SOME SELECTED INSTRUMENTS

  • CLINITEK 50 & CLINITEK STATUS
    • well  suited  for  small  volume  laboratories  and  physician’s offices
    • Memory storage for test results -100 for Clinitek 50 and 200 for Clinitek Status
    • automated  reading  of  microalbumin-to-creatinine  and  protein-to-creatinine  ratios and human  chorionic  gonadotropin  (hCG)
  • CLINITEK 200
    • For medium-volume to large-volume urinalysis laboratories and features a high specimen output of one strip every 10 seconds.
    • Multistix reagent test  strips  are  used,  and  the  instrument  has  the  ability  to report semiquantitative (mg/dL) results or plus (+) and SI units.
    • The reflectometer  is  calibrated  daily  and maintenance is required each day for all areas in contact with urine test strips
  • SYSMEX UF-SERIES
    • Fully automated sample analysis with automatic classification of all 10 formed element groups with SCATTERGRAMS and HISTOGRAMS for reference
    • Laser-based FLOW CYTOMETRY along with impedance detection, forward light scatter, and fluorescence
    • Sample is stained with 2 dyes
      • PHENATHRIDINE – orange dye, stains DNA
      • CARBOCYANINE – green dye, stains nuclear membranes, mitochondria, and negatively charged cell membranes
  • SYSMEX UF-SERIES
    • Stained sample is passed through the flow cell, where it is HYDRODYNAMICALLY FOCUSED and presented to a laser light beam that produces fluorescence and light scatter
    • Particles are identified by measuring the change in impedance of the sediment elements, as well as the height and width of the fluorescent and light scatter signals, which are presented in scattergrams and histograms
  • iQ 200 Automated Urine Microscopy Analyzer (IRIS)
    • Automatically analyses and classifies urine particles into 12 categories
    • Uses AUTO PARTICLE RECOGNITION (APR) software that classifies urine particles in the photographs based on size, shape, texture, and contrast
Automated Body Fluid Analysis Systems
  • cells are first mixed with reagent fixative and then counted
  • differentials counting enumerates numbers of neutrophils, lymphocytes, monocytes, and eosinophils
  • automated cell counters use larger numbers of cells, enhancing precision and accuracy
BODY FLUID ANALYZERSFDA APPROVED FOR USE WITH THESE FLUIDS:
Iris iQ Body Fluid ModuleCSF, Pleural & Peritoneal Peritoneal lavage, peritoneal dialysate, pericardial, general serous fluids, synovial
Siemens Medical Solutions Diagnostics ADVIA120 and 2120CSF
Sysmex XE-5000 Automated Hematology SystemCSF Serous body fluids Synovial fluid
Medical Electronic SystemsSemen

ADVIA120 Hematology System

  • First automated instrument with an FDA-approved automated CSF assay
    • Uses flow cytometry, light scatter, and absorbance to count the RBCs, WBCs, and performs a WBC differential that includes percentages and absolute numbers of mononuclear cells and PMNs on samples with >20WBCs/µL

AUTOMATION OF SEMEN ANALYSIS

  • SQA-V automates sperm counts and motility
    • has a two-channel measurement system that interacts with a specially designed testing capillary that contains the semen sample
    • one channel  “measures”  light  absorption  and  refraction  in sperm cells and translates this into concentration
    • one channel “counts”  light  interruptions  (signals)  caused  by sperm  cells  moving  across  the  field  of  light
    • In approximately 1 minute, thousands of signals are “read” resulting in exceptional accuracy and precision.
    • Automating the motility analysis eliminates reader subjectivity and variance among technologists.

AUTOMATION OF URINE PREGNANCY

  • Quantitative human chorionic gonadotropin (HCG) is one such test that is interpreted by the VEDALAB Easy Reader.
    • Immunochromatographic rapid test cards are read by the meter using a high-resolution CCD camera.
    • Integrated software analyzes the images and records the results.

Author:

Hi! I am an anime-loving registered medical technologist turned doctor of medicine. Oh yeah, I teach medtech and life. Hihi. ^o^ Yoroshiku.

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